1. Field of the Invention
The present invention relates to a pressure control valve for a fuel delivery unit having a housing having a valve seat, a closing part arranged in the housing and movable against the valve seat, and a spring which is supported on a counterholder connected to the housing for prestressing the closing part. The present invention further relates to a ventilation valve for a fuel delivery unit having a housing with a valve seat, a closing part arranged in the housing and movable against the valve seat, and a spring for prestressing the closing part, the spring having smaller dimensions than the closing part.
2. Description of the Related Art
Valves having closing parts prestressed by springs are frequently used in known fuel delivery units as pressure control valves or as ventilation valves and are known in practice. The housings of these valves are designed as cup-shaped deformations in a housing part closing the delivery unit. The housing of the known pressure control valve is made of a tubular design for accommodating the closing part, which is designed as a ball, and the spring. After the closing part and the spring are installed, the housing is closed by a counterholder which is designed as a cap. The counterholder has slots through which fuel flows and centering elements for centering the spring and latching elements in the housing. In the known ventilation valve, only the spring is located within the housing. The valve seat is arranged on an outer side of the end of the housing which lies opposite the counterholder. Components located below the housing part of the delivery unit restrict the travel of the closing part. During installation, the travel of the closing part is restricted by a clamp.
A problem with the known valves is that they are complicated to fit and have components which are cost-intensive to manufacture. For example, the counterholder which is designed as a cap and the clamp required for restricting the travel of the closing part are each very complicated components. Furthermore, the components of the known valve have to be fitted precisely in their intended orientations. This requirement for precise fit makes automatic installation of the valves difficult.